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Cable Loss
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D |
Digidesign Audio Engine is the underlying code that allows Digidesign software communicate with computer platforms and operating systems. DAE is required for third party software to access Digidesign hardware. Prior to HD systems, DAE was an actual separate application. For HD systems, DAE is now integrated into the Pro Tools application.
Digital Audio Tape. A two track 16-bit digital recording and
playback system.
Digital Audio Workstation. Usually refers to a computer with
audio recording, playback and editing features. Nowadays,
entire projects can be completed on DAW.
Digital to Analog converter. The opposite of an A/D
converter where audio signals in the form of digital data
are reconstructed back into an analog waveform. As with
ADCs, DACs come in a variety of configurations and prices
ranges, and vary in how faithfully the program material is
reassembled.
(See
Jitter)
The decibel (abbreviated dB) is a unit used to measure the
intensity of a sound. However, the dB scale is not linear,
rather it is a unit used to express the relative levels of
two electrical voltages, powers or sounds. It is never an
absolute value.
Also sometimes referred to as dBv, it is dB referenced to
voltage. 0dB equals 0.775 volts.
dBV also references voltage, but does so without regard for
impedance. 0dB equals 1 volt. The dBV rating is most
commonly found in reference to consumer equipment that uses
operating levels of -10 dBV.
An imbalance that can sometimes occur at an A/D converter,
where DC (direct current) which is basically a constant
voltage, is introduced into the digitized signal. Apart from
reducing headroom, DC content can introduce clicks and pops
while the audio is being edited.
A recordable DVD disc. Not to be confused with DVD-RAM and
DVD-RW, both of which are rewritable mediums. DVD-R is a
write once, read many medium which currently holds about 4.7
gigabytes of information.
A type of DVD
media that is designed for storage and backup. No other
equipment other than the drive itself is required for a user
to use DVD-RAM. In fact, DVD-RAM discs act very much like
hard drives, other than being a much slower medium, in that
a user can simple drag and drop files on to the desktop
icon.
In reference to power amplifiers, the damping specification
is the ability of the amplifier to control speaker motion
once signal has stopped. The effects of damping are most
apparent at low frequencies - an amplifier with a high
damping factor will make a speaker sound "tighter" in the
low end, while low damping factors result in indistinct
bass.
Device for reducing the effect of sibilance in vocal
signals. Basically, a de-esser is a frequency dependent
compressor, although these days such devices are very
sophisticated and optimized in the way they tackle the
problem of sibilance.
Physical click
stop in a control knob/switch such as a pan or EQ cut/boost
knob.
The portion of a microphone that is mechanically moved by
sound waves. The resulting interaction with a backplate or
moving coil (depending on the microphone type) allows the
conversion of sound energy to electrical energy. This energy
eventually gets to a loudspeaker or headphone, where a
roughly equivalent reverse process takes place as the cone
moves in response to the electrical signal and produces
sound energy.
A type of antenna with two defined opposing radiating
elements, both of the proper length for the frequency of
operation, and each forming a counterpoise for the other.
Often abbreviated as DI (short for Direct Inject) used
primarily as a device for matching the impedance of a source
to the inputs of a tape machine or mixer. Typically, the
output of a bass or electric guitar is a high impedance,
unbalanced signal, that needs to be converted into a low
impedance balanced signal, either for long cable runs to a
live console, or for imputing into a recording device. The
process also allows the electronics on these instruments to
function at their correct levels, thus often improving the
sound.
The property of transmitting /receiving energy more strongly
from/to certain directions, than others.
A method of "burning" a CD, disc-at-once writes to the disc
in one pass - the laser in the CD burner never turns off,
even in silent passages. Required by mass duplicators of Red
Book audio CDs. Although CDs written track-at-once will
generally play in consumer CD players, the duplicators at
mass manufacturers will reject such a disc as fatally
flawed.
A term that has taken on a specific meaning, but which is in
fact much broader in its definition. Technically, distortion
is any change in the shape of an audio waveform compared
between two points in a signal chain. Therefore adding EQ
and compression also adds distortion to the original signal.
But generally the term refers to the desirable or
undesirable "breaking-up" of audio (as in distorted
guitars.)
A method of reception providing protection from signal loss
due to multi-path nulls, which are localized small areas
with a very low RF signal level caused by multi-path
propagation.
The taking of a audio file with a high sample rate, and
sample rate converting down to a lower sample rate. Used in
particular when a project is recorded at a high sample rate
and the audio files need to be prepared for CD distribution.
In wireless microphones, a loss of RF signal, which in turn
results in loss of audio or audio that is noticeably noisy.
Also refers to a small physical area where there is
insufficient RF signal present to obtain satisfactory
wireless operation. Dropouts are normally caused by
multi-path or signal blockage due to some type of
obstruction. Also refers to areas on oxide tape where there
is a problem with the coating and where subsequently audio
or digital data is not properly reproduced.
Piece of software that handles communications between the
main program and a hardware peripheral, such as a soundcard,
printer or scanner. Drivers are constantly being updated due
to OS rewrites and the like.
Refers to a
type of multi-pin connector that is commonly used for
computer connectivity, although in last few years
manufactures such as Tascam and Digidesign use the
D-Subminiature connector for supplying multi-channel audio
to and from their systems.
A system for
controlling the level of one audio signal with another. For
example, background music can be made to "duck" whenever
there is the need to hear a voice over.
A type of microphone that consists of a diaphragm connected
to a coil that operates in a magnetic field. Any movement of
the diaphragm due to sound pressure levels moves the coil
within the magnet, thus producing an electric current.
Dynamic microphones do not require external power to
operate, are generally more robust, and therefore favored
for live use (although several manufactures are making
condenser microphones specifically for live use.) The
downside is that due to their construction, dynamic
microphones are less sensitive to fast transients and don't
have the high frequency response of the condenser variety.
The range in dB between the noise floor of a device and its
defined maximum output level. The term applies to both audio
devices and RF equipment.
E |
Acronym for Enhanced Audio Streaming Interface developed by
Emagic, and is designed to standardize communication between
audio software and hardware. The standard is cross-platform
and is similar to ASIO, developed by Steinberg, but differs
from ASIO in that Emagic has made EASI totally public, with
no need to sign non-disclosure agreements.
EIN is a specification that is mostly relevant to
microphones and preamplifiers. It stands for Equivalent
Input Noise and deals with the self noise that is a feature
of virtually every piece of electronics. Since microphones
output a low-level signal, any noise present will be boosted
proportionately. The specification is usually measured with
a 200ohm source resistance, which on its own produces a
level of noise that when referenced to a line level signal
is equal to -129.6dBu of noise. This is theoretically the
lowest noise level that can be obtained, but some
manufactures play with this figure a little by measuring
their equipment with lower source impedance.
The initial sound reflections from walls, floor and ceiling,
created when an acoustic event happens in an acoustically
reflective environment. Often a parameter that can be
adjusted in units that electronically simulate acoustic
spaces (reverb processors.)
As the name implies, a variation on a condenser microphone,
but with a permanently charged plate in the capsule. This
negates having to supply external power to the microphone.
(See
Condenser Microphone)
In wireless microphones, the radiation of an RF signal,
whether intentional or not.
Originally design to add back some of the high-frequency
content lost in audio production due to multiple passes
using analog tape. Techniques used include dynamic
equalization, phase shifting and harmonic generation.
All sounds can be described in a variety of ways. One of
them is the manner in which a sound evolves amplitude-wise,
starting from silence to full volume to final decay. Or how
the harmonic content changes over time. In synthesizers,
these changes to an oscillator or filter are achieved using
envelope generators. EG have various break points supplied
to help adjust the rates and levels of the various parts of
the envelope.
Hardware device or computer plug-in used to alter the
frequency balance of an audio source. An equalizer has the
ability to boost or cut specific frequency ranges based
around a center frequency and can be used either creatively,
to drastically alter a source, or in a corrective manner,
such as in a mastering situation, to even out anomalies in a
mix. Equalizers come in various forms, including parametric
and graphic, active or passive.
(See
Filter,
Graphic,
Parametric)
Synthesizer with no keyboard, often rack mountable or in
some other compact form. Useful for users who already have a
keyboard and do want another one, but want the sounds
offered.
In wireless microphones, the process of restoring the
original dynamic range of the audio signal by means of a 1:2
logarithmic expander.
F |
Field-Effect Transistor typically used as an impedance
converter at the element in a condenser microphone. A MOSFET
is a particular kind of FET, which is finding itself used
more and more in power amplifiers.
(See
MOSFET)
In acoustics, the undesirable leakage of audio from
loudspeakers, back into the same microphone which is being
used for originally capturing the audio. If too much
feedback occurs, the system can go into self-oscillation,
causing unpleasant howling or squealing. In electronics,
such as power amplifiers, feedback can be used to achieve
specific results, such as performing input/output
comparisons.
An automatic electronic device that senses the onset of
feedback, and cancels it before it gets out of hand. This is
achieved by using a specialized equalizer with multiple,
very narrow filter bands, positioned between the audio
source and the speakers. The unit "searches" for the
beginnings of feedback, analyzes the problem frequency and
cuts that band. Good eliminators carry out this whole
process in mere milliseconds, and can respond to the fact
that feedback may occur at many different frequencies
throughout a live performance.
A microphone polar pattern whereby the capsule is most
sensitive to sound sources from the front and back equally,
but sounds from the sides of the microphone are rejected.
Sometime referred to as bi-directional. Also describes
certain antenna patterns, such as that of a dipole.
An electronic circuit designed to attenuate a sound source's
energy at a particular frequency. A true filter is always
passive, in that it does nothing to add to the signal.
However, most filters these days have amplifiers attached to
them to allow the user to both boost and cut particular
frequencies (active filters.) Multiple filters can be
combined to create equalizers that are either passive,
active or both.
(See
Equalizer)
Apple computer's version of the IEEE 1394 standard, which is
a high-speed data exchange protocol. FireWire provides a
single plug-and-socket connection on which up to 63 devices
can be hung. Additionally, the technology allows for
hot-swapping devices, while data transfer allows for speeds
of up to 400 Megabits per second. Common on personal
computers these days, FireWire is also finding its way into
consumer electronics, particularly digital video.
(See
IEEE-1394)
Flanging is an audio process where two copies of the same
signal are played together, with one variably delayed
against the other. Originally created using two tape
machines and "leaning" gently on the flange of one of the
tape reels, today the effect is produced using digital
effect processors. Feeding the processed signal back into
the device to be processed again can deliver a more intense
effect, although many are of the opinion that the original
tape based method is still superior.
A data encoding process that allows the representation of
very large numbers with fewer bits. Used in computers that
have floating point registers, and where complex graphics,
scientific or audio processes need to be executed rapidly.
As far as audio is concerned, a debate is presently centered
around whether floating point or fixed-point computation is
better for the end product, in terms of sonics. So far there
does not seem to be a consensus on this issue, since there
are advantages and disadvantages to both systems.
(See
Bit Depth)
Originally developed by John Chowning of Stanford
University, and later popularized by Yamaha's FM7
synthesizer, FM synthesis is a method of sound generation
where a sine wave is modulated by one or more sine waves to
produced a large variety of waveforms. Later incarnations of
the process used many other types of waveforms for the
carrier and modulators, producing an even wider palette of
sounds. Know primarily for the pure bell-like and electronic
piano tones
An emphasized frequency component of an instrumental or
vocal sound that does not change with pitch, and which helps
to distinguishes one instrument from another, and gives
voices their unique characteristic. Problems arise in the
audio world where pitch shifting is common, (samplers, DAW
editing) since in this case the formant characteristic is
pitch-shifted along with the overall pitch of the signal,
making the resulting audio file sound unnatural. Various
manufactures of pitch shifting processors have tried to
address this issue with a modicum of success.
The process by which data written to a hard drive is stored
in small packets that may or may not be next to each other.
The result of continual erasing and saving from/to the hard
drive, severe fragmentation can cause a slowdown in drive
performance with drive intensive applications like digital
audio, since the head mechanism has to constantly jump
around to read all the data.
In audio the indication of how many cycles of a repetitive
waveform occurs during one second. A waveform which repeats
once per each second has a frequency of 1Hz (Hertz.)
Frequency also references to human hearing as pitch.
A measurement of the frequency range that can be handled by
a specific piece of electrical equipment or loudspeaker when
referenced to amplitude. A graph of all the frequencies
plotted versus level is the Frequency Response Curve of a
particular piece of equipment.
In wireless applications, the accuracy to which the
operating frequency is maintained over time and in the
presence of environmental changes.
A circuit to generate a stable and precise RF output on any
one of a number of preset (or programmable) frequencies.
Synthesizers are used as the local oscillators for
receivers, and to set the output frequency of transmitters.
G |
An extension to the General MIDI protocol developed by
Roland for use in its own synthesizers.
The extent to
which a circuit amplifies a signal. Usually part of an
amplifier specification, its value is most often expressed
in a decibel value.
The amount of total gain that can be achieved in an audio
system, from microphone to speakers, before the onset of
acoustic feedback.
A dynamic device that has the ability to stop audio passing
through it based on a certain threshold. Originally designed
to shut down audio output in passages with no program
material (where tape hiss might be evident) or to lower
bleed on drum microphones. Gates can also been used
creatively, notably the gated reverb of Phil Collins' 80s
drum sound.
An addition to the original MIDI specification that allows
for consistent playback on any instrument that is GM
compatible. Achieved by requiring that groups of sounds have
very specific locations (a piano sound on one synthesizer
will have the same location on another,) that all
instruments have 24-voice polyphony, and that certain
continuous controllers are similarly defined. In theory,
music sequenced for General MIDI should play back on any
other GM instruments with the similar type of sound on the
same MIDI track with any volume and pan information also
being executed as written.
(See
MIDI)
A flexible metal coupling that is used to attach a
microphone to a stand or podium. Used mostly in conferencing
and for podium mounting, the metal spiral allows the
microphone to be adjusted into a multitude of positions.
The term
nowadays refers to a type of equalizer where 15 or more,
narrow frequency bands are controlled using sliders, either
boosting or cutting the individual bands. The term graphic
came about because the arrangement of the sliders provides a
visual representation of the EQ curve. Graphic equalizers
can still be found that use rotary controls instead of
faders.
The loss of operating distance due to the positioning of
wireless antennas too close to the ground. Reflected RF
energy from the ground gets mixed in with the direct RF
signal and causes cancellation of RF energy at the antenna.
In certain situations the loss can be significant. UHF
systems are less susceptible to this effect than are systems
that use VHF, due to the shorter wavelength of the former.
A switch found on some equipment that disconnects the shield
of a balanced cable from the local equipment ground. Used in
situations where ground loops are problem.
A condition
where current circulates in the ground wiring system, due
either to the grounds at the end of a length of cable being
at different AC potential, or where a video or audio system
has multiple paths to ground. Manifests itself usually by
varying levels of hum (in audio systems) or as rolling bars
in the picture of a video system. One way to deal with it is
to use ground lift switches, but generally it is better to
find the offending piece of equipment and then checking it
to find out why it is causing the ground hum.
H |
In search of the ultimate "piano-feel keyboard" synthesizer
manufacturers have often employed weights on the back-end of
individual keys to simulate the action of real pianos.
However, to really achieve a similar feel, certain
manufacturers have resorted to installing hammers on the end
of the keys, which when the key is struck, moves the hammer
to strike a surface. The resulting feel is much closer to
that of a piano's actual playing action.
A wireless microphone transmitter consisting of both the
microphone and the transmitter electronics in one integrated
package.
Refers to the sensitivity that a microphone exhibits to
movement, the actual holding of the microphone and shock. A
microphone's ability to lower handling noise is a direct
result of the construction of the microphone, and to that
end, some manufactures employ internal shock mounts for the
capsules to eliminate as much handling noise as possible.
A high
capacity computer storage device that is based on a rotating
rigid disk with a magnetic coating onto which data may be
recorded. The hard disc drive should technically refer only
to the mechanism that controls the positioning, reading, and
writing of the hard disc, but today hard disc, disc drive
etc. are terms that are commonly used for the combination of
the two parts.
(See
IDE,
SCSI,
Seek Time)
A harmonic is a wave whose frequency bears a whole number
relationship to the frequency of a reference signal. Complex
sounds, such as the human voice or the sound of a stringed
instrument always consist of a fundamental frequency and
then a number of harmonics, which, depending on their
amplitude, will make up the basic characteristic of that
sound. So the second harmonic is always two times the
fundamental, and so on through the rest of the harmonic
series. Discordant sounds have several or many harmonic
waveforms that do not bear the whole integer relationship
present in the basic sound.
The result of passing audio through some electronic device.
Since it is impossible to make a perfectly linear device
(audio out exactly matches audio in) harmonic distortion is
always a byproduct of signal processing. The amount of
distortion a particular piece of electronics creates is in
most cases kept as low as possible, particularly in
reference to "transparent" microphone preamplifiers.
However, sometimes the "coloring" is acceptable and indeed
favored, and can be taken to extremes.
The difference expressed in dB between the nominal operating
level of a device, and the maximum level that can pass
through the device without being distorted.
A small microphone mounted on a short boom and held in place
close to the performer's mouth by a headband or similar
device. Used by performers who need their hands free during
dance numbers or to play an instrument.
A type of antenna formed by a coiled small-diameter spring, usually covered in plastic and somewhat flexible. Physically shorter than a standard 1/4-wavelength whip antenna, but also considerably less efficient.
A unit of frequency, named after Heinrich Hertz, a 19th
century German physicist. So if a complete single cycle of a
waveform occurs over 1 second, the waveform is said to have
a frequency of 1Hz.
A filter that attenuates frequencies below a certain cutoff
point, while passing on frequencies above the cutoff
unaffected. Sometimes referred to as low-cut filter.
(See
Filter)
Used in reference to computer based recording systems. In
the early days of computer recording, much of the processing
work had to be done on additional hardware cards, while the
computer merely provided visual feedback. But because of the
unprecedented power that is available in today's computers,
it is entirely possible to have a virtual studio within the
computer, using only the computers processing power. Host
based systems are still hampered to some degree when
compared to their hardware card equivalents, but as computer
power increases, so host based systems become more and more
economical.
A type of audio connector often used for the microphone
connections on wireless body-pack transmitters. The
connector wiring is not standardized within the wireless
industry. Also referred to as a Hirose Connector
A type of microphone pick-up pattern. Similar in shape to a
cardioid pattern, except that the sides have the greatest
amount of rejection, as opposed to a cardioid pattern where
the rear of the microphone has the least sensitivity.
(See
Cardioid)
I |
Integrated Drive Electronics is a standard electronic
interface that is used as a data path for a computer's disc
storage devices. IDE drives are cheaper and less expensive
to implement when compared with SCSI drives. And whereas
SCSI drives have traditionally been viewed as more robust
and quicker than the IDE counterparts, the gap between them
is shrinking due to the general reliability of hard drives
in general. Apple suspended the use of the SCSI interface in
their computers several years ago, and now provides the
cheaper EIDE bus, which is an enhanced version of IDE.
(See
SCSI)
A high-speed data exchange protocol, it provides a single
plug-and-socket connection on which up to 63 devices can be
hung. Additionally, the technology allows for hot-swapping
devices, while data transfer allows for speeds of up to 400
Megabits per second. Common on personal computers these
days, IEEE 1394 is implemented by Apple as FireWire, and by
Sony as iLINK.
(See
Firewire)
Intermediate Frequency. Wireless receivers normally convert the incoming RF signal to a lower intermediate frequency for amplification and final filtering prior to demodulation.
Abbreviation for input/output. In audio, the term refers to
the physical inputs/outputs of a particular piece of
equipment. Also used to describe any operation, program or
device that transfers data to and from a computer.
In receivers, the process of converting the desired RF frequency results in an undesired sensitivity at a second RF frequency, which is referred to as the image frequency. RF filtering in the receiver is relied upon to reduce to acceptable levels the receiver's susceptibility to spurious RF signals at the image frequency.
The measure of a receiver's ability to reject signals at its
image frequency. Normally expressed as the ratio, in dB, of
the receiver's sensitivity at the desired frequency versus
the sensitivity at the image frequency.
An expression of the opposition that an electronic
component, circuit or system offers to AC or DC current.
Impedance contains both resistive and reactive components,
although generally only the resistive part of the circuit is
usually quote in specifications as Ohms. So the higher the
resistance, the higher the impedance.
To restore a piece of equipment to its factory default
settings.
A connector at a particular point of a circuit that allows
for the introduction of a piece of external equipment, so
that the original signal now flows and is processed by the
external equipment prior to being returned back into the
original circuit.
A measure of the inter-modulation performance of a RF
devices. Devices with high intercept points will generate
lower levels of undesirable inter-modulation products as
compared to similar devices with lower intercept points.
A device that acts as an intermediary to two or more pieces
of equipment. An audio interface for a computer allows
signals generated by a preamplifier for example, to be
communicated to the computer software. The software itself
is also an interface, but in this instance it is between the
operator and the computer itself.
A process that can result in distortion. Inter-modulation is
the result of two or more frequencies inter-reacting with
themselves and generating new frequencies that are not
present in the original signal. These are invariably based
on the sum and difference of the original frequencies.
The process in IT (information technology) that requires
near exact timing coordination to successfully transmit
information, such as video or audio data. Isochronous data
transfer ensures that data flows continuously and at a
steady rate so that the receiving mechanism can display the
result without interruption.
An isotropic radiator is a transducer that produces useful
electromagnetic field output in all directions with equal
intensity, and at 100% efficiency. In wireless applications
the isotropic radiator is theoretical, although the dipole
antenna roughly approximates it. It is used as a standard
reference source against which the performance of other
antennas is measured.
J |
Jam Sync is a setting that is selectable when using a
synchronization device with SMPTE time code. It allows the
receiving synchronizer to regenerate time code if there are
errors or drop outs in the original code. If jam sync is not
used, then a drop out will cause the slave device to go off
line.
(See
SMPTE Time Code)
Jitter is the deviation of some aspect of the pulses in a
digital signal. In audio applications, Analog to Digital
converters are one of the most critical components that are
susceptible to jitter. Using an internal or external clock,
an A/D converter "slices" an incoming audio signal into a
number of pulses that digitally conforms to the original
source. These pulses have to occur and proceed with very
strict timing, and any periodic displacement of the signal
from its ideal location will cause jitter. Jitter can be
caused by the converter having a poor clock, or when source
impedance is incorrectly matched at the load. The results
are heard as low level distortion or noise, and since high
frequencies are more susceptible to jitter, a loss of high
end definition. The issue is that once jitter has been
introduced into the digital data it is impossible to remove
it.
(See
A/D Converter,
D/A Converter)
A physical controller that allows a tape machine's transport
to move tape back and forth a small distance to find an edit
point. Originally used by video editors to find an exact
location on tape, jog wheels can be found on audio control
surfaces to provide similar functionality within a digital
audio editor.
Gamers have traditionally used joysticks for controlling
games. It is a device that allows control of two different
axes simultaneously. Certain synthesizer manufacturers have
utilized the principle instead of using separate modulation
and pitch wheels, but the main usage of the device is now
beginning to appear in surround sound production. Pan pots
are two- dimensional devices (left/right,) and since
surround sound requires at least four points to define an
audio source location (left/right/front and
left/right/rear,) joysticks are a common feature on surround
consoles and control surfaces.
K |
The kilohertz is a unit of alternating current or
electromagnetic wave frequency equal to one thousand hertz.
The unit is used in measurements of bandwidth, but in audio
can also refer to the pitch of a particular tone.
Term is used in reference to a synthesizer or sampler that
uses sample data for the raw building blocks of the sound
generation. It is a means to assign each sample to a
particular key or range of keys. So a piano keymap would
theoretically have each tone from the entire piano keyboard
mapped to exactly the same keys on the synthesizer or
sampler. A second keymap might contain similar information,
except that each note was sampled using a stronger/lighter
strike of the piano keys. Of course, it is not always
necessary to assign one sample per key. In fact one could
assign a single sample across the entire keymap. Different
manufactures refer to keymaps by other names, such as Key
Group or multi-sample.
L |
Liquid Crystal Display. A technology used for displays in notebook and other small computers, all the way to advanced VGA computer screens. It is also found on lower cost electronic music devices. LCD's are generally manufactured utilizing a single crystal plate and a specific pattern of electrodes. Applying voltage between the electrodes changes the phase of the light travelling through, or reflected by the material, thus altering the information displayed.
Light Emitting Diode. A semiconductor device that emits
light when an electric current passes through it. Used for
status lights or bar graph meters in many audio devices,
LED's are also found everywhere from watches to laser disc
players. Some LED's emit infra red energy and are found in
remote control devices and wireless headphone systems.
Low Frequency Oscillator. An oscillator that is designed
primarily to operate below the threshold of human hearing
(though not exclusively) and to provide modulation function.
Often found in synthesizers and effect devices. For
instance, vibrato, a cyclic variation of pitch is generated
by modulating the audible portion of the signal with an LFO
which, depending on its pitch of the LFO, will create a
slower or faster vibrato.
Latency is an issue that can be found in several areas of
audio production. In its broadest sense it means the delay
that increases response time beyond the time desired. For
instance, in a MIDI keyboard instrument, there is a slight
delay, or latency, between when a key is struck and when the
actual sound is produced. In computer based recording
systems that use native processing, a delay exists between
an audio event being imputed, and when the same event
arrives at the monitoring stage. The delay will increase if
the computer has to deal with any real-time processing. To
avoid the discomfort that is experienced by this delay, many
systems employ input-only monitoring during overdubbing.
A type of miniature microphone that is usually worn fastened
to clothing or hung around the neck. Designed for situations
where a microphone would be obtrusive, such as film sets or
TV talk shows, the microphone is typically made with a steep
high pass filter to reduce noise generated from the
microphone moving against clothing. Also know as a clip-on
or lapel microphone.
An optical cable. The term was originally coined by Alesis
to differentiate between their 8-channel protocol and the
2-channel optical connectors found on CD players and DAT
recorders. The actual fiber optic cable used is the same in
both cases, only the form of the transmission is different.
(See
ADAT Optical)
Similar in principle to a compressor, a limiter is an audio
processor that prevents the amplitude of an audio signal
from rising above a certain threshold, regardless of what is
happening to the amplitude of the source audio. Dynamics
below the threshold are more or less unaffected. Certain
compressors can in fact function as limiters if their ratio
can be set to infinity:1. Uses for limiters include
maximizing levels for CD release, optimizing recording
levels for imputing into a DAW or when going to tape, or to
protect users of in-ear monitors from sudden volume surges.
(See
Compressor)
Although the term refers to the average level of a signal,
these days use of the term is more specific and applies to
the two line level references, balanced and unbalanced.
Balanced or professional equipment operates at +4dBm or 1.23
volts, while unbalanced or semi-professional equipment
operates at -10dBV or 0.32 volts. Although the distinction
between professional and semi professional equipment is
blurring, the important fact is th
